The answer to the first question is no, he was not, according to
Eric Jackson at Forbes based on a study of CEO narcissism.
The answer to the second question is, yes, it does matter quite a
bit. Narcissistic CEOs have destructive tendencies that can ruin
companies.

In the first study, the researchers looked at 111 CEOs in the
computer/software industries from 1992 to 2004. They first
defined narcissists as having "feelings of superiority,
entitlement, and a constant need for attention and admiration"
and found that:

"The narcissist is not content with being eventually praised for
a success long-in-the-coming, but instead needs applause
at frequent intervals. To obtain such applause, the
narcissist must regularly undertake challenging or bold
tasks that are highly visible to a respected audience;
those tasks must be of the type that will earn admiration for
their inherent boldness. In a related vein, narcissists
are especially susceptible to boredom and engage in various forms
of “sensation-seeking." Therefore, narcissists favor the
extreme, the grandiose, and the colorful. Discreet or incremental
actions are not satisfying."

Penn State

Narcissistic CEOs make hugely different strategic choices for
their companies than non-narcissistic CEOs. They're more likely
to take big risks, more frequent risks, and make moves that will
get lots of public attention. This means their company's
performance is more volatile; and these CEOs tend to engage in
more mergers and acquisitions. The researchers also created a
5-item index to measure CEO narcissism, which considers these
factors:

1) The prominence of the CEO’s photograph in the company’s annual
report.
2) The CEO’s prominence in the company’s press releases.
3) The CEO’s use of first person singular pronouns in
interviews.
4) The CEO’s cash compensation divided by that of the
second-highest paid executive in the firm.
5) The CEO’s non-cash compensation divided by that of the
second-highest paid executive in the firm.

Jackson notes that narcissistic CEOs spend more on advertising
and R&D and take on more debt, even when their company and/or
the economy is tanking. He also argues that Steve Jobs doesn't qualify as a narcissistic
CEO because although he did the big product announcements,
he put his colleagues' names in the press releases; he
surrounded himself with smart people who could counter his
ideas; he used more "wes" than "Is" in his vocabulary; and he
created
a detailed succession plan for Tim Cook.